/**
 * @param <T> Generic type.
 * @author Lukas Koell
 * @author David Medenjak
 * @author Johannes Riedmann
 */
public interface TreeIter<T> extends Iter<T>{
    /**
     * Creates an iterator for a subtree.
     * @return TreeIterator<T> which contains the nodes of the subtree in BFS order
     */
    public TreeIter<T> down();
}
